<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script type="text/javascript">
			// js的代码是 读一句 执行一句
			
			var num = 1
			console.log(num)
			
			num = 2
			console.log(num)
			
			
			num = 3
			console.log(num)
			
		</script>
	</body>
</html>
